Underkeep Mushroom for Improvement Quest Guide: All 5 Mushroom Locations & Branch Outcomes
A complete walkthrough of the Underkeep mushroom for improvement quest: where all five mushrooms hide, how to break the rubble pile, and both hand-in outcomes explained.
Few side quests in a retro dungeon crawler sound as harmless as the Underkeep mushroom for improvement errand, and few turn out this strange. What begins with the cook asking for a handful of fresh caps becomes the Underkeep mushroom for improvement quest line: five mushrooms scattered across a forest and a cave, one pickaxe-gated rubble pile, and two hand-in outcomes whose effect on demo completion remains disputed. For reference only, accounts conflict on whether the mushroom transformation ends the demo or allows play to continue afterward. If you have been circling the same tunnels looking for that last cap, this guide covers every location, the interaction most people get wrong, and what each reward actually costs you.
What the Underkeep Mushroom for Improvement Quest Actually Asks
In the demo, the cook opens the game with a simple request: his mushroom supplies are low, so he sends your party into the nearby forest to bring back a handful of caps in exchange for a hot meal and, in his words, something extra. That hook is what players nicknamed the "Mushroom for Improvement" quest, borrowing the title used in a widely shared demo playthrough on YouTube.
Two things complicate it:
- You need five mushrooms, not three or four. Community reports on the Steam discussion thread asking for a full mushroom guide confirm the demo total is five: two outdoors and three inside the cave or mine.
- A second quest-giver wants the same caps. Partway into the dungeon you meet a fungal creature who says it senses kin nearby and asks you to return the "little ones" you have gathered. Accepting updates the quest, and from that point the Underkeep mushroom for improvement objective can be resolved in more than one direction.
The demo itself is a first-person, grid-based, party-based crawler in the 90s tradition, with turn-based combat, shared gold and food, and rest-based healing. Chasing Dings' February 27, 2026 Steam Next Fest write-up described it as the more immediately fun of the two crawlers featured, praising the retro vibe. Check the Underkeep Steam page for the current build and release status before planning a run around demo-only content.
All Five Mushroom Locations, Step by Step
The map is small, but two of the five caps are effectively hidden behind interactions rather than distance. Here is the full set, cross-checked against community reports and recorded playthroughs.
| # | Area | Where It Is | How to Grab It |
|---|---|---|---|
| 1 | Forest, near the start | First fork right at the beginning, to your left / south of the resurrection shrine | Walk onto the tile and pick it up |
| 2 | Forest glade | North-western corner of the clearing where the merchant is fighting rats | Grab it before or after the fight |
| 3 | Dungeon | At the fork with the first purple worm, head north to a chamber with a bush lit by a sunbeam | The mushroom sits on the same tile as the bush |
| 4 | Dungeon | East corridor from the sunlit bush chamber, into a room with crates and barrels | Smash the crates |
| 5 | Dungeon | South of the first purple worm fork, behind a pile of fallen rock | Collect the pickaxe first, then left-click the rubble |
The two caps that trip people up
Mushroom #4 is not lying on the floor. You have to break the crates, which the tutorial does teach, so most players find it once they think to swing at scenery. Edelweiss on the Steam forums noted that the crate and rubble mushrooms are "kinda hidden" despite the rest of the set being in plain sight.
Mushroom #5 is the real wall. The rubble pile reads as scenery to a lot of players, and the pickaxe you need is found in the chamber with the humanoid mushroom creature, so a player who backs away from that encounter without looting the room can end up walking past the pile five times.
Why Left-Clicking the Rubble Beats Swinging Your Sword
This is the single most repeated mistake in the Underkeep mushroom for improvement quest. Community reports are blunt about it: hitting the rockslide with weapons does not work. Neither does right-clicking it. Toth Amon on the Steam forums admitted trying "everything but, apparently, left clicking on the rock pile," and another player, LordIvan, replied that they had made the exact same error.
The reliable sequence is:
- Find the humanoid mushroom in the dungeon chamber and take the pickaxe into your inventory. You cannot equip it, so do not go looking for an equipment slot.
- Walk to the rubble pile south of the first purple worm fork.
- Left-click the rock pile. It clears, and the fifth mushroom is behind it.
A player in the same thread suggested a pop-up hint along the lines of "if only we had a digging tool," noting that crates get a tutorial but rubble does not. A developer reply from sirrobbo on March 1 called it a good point and said the team could "definitely consider adding a subtle hint for rubble or blocked paths." Until that lands, treat any suspicious rockfall as interactive and click it first.
Two Hand-In Outcomes, One Set of Mushrooms
Once all five caps are in your pack, the Underkeep mushroom for improvement quest forces a choice. Your inventory holds one set of mushrooms, so you cannot satisfy both quest-givers in a single run.
| Outcome | What You Do | What You Get |
|---|---|---|
| The creature's reward | Hand the five caps to the fungal figure | A vision of the Underkeep and its buried tower, ending with your party transformed into cheerful mushroom people |
| The cook's reward | Give the caps to the cook | A stew-or-roast thank-you and his usual enthusiastic reward |
| The violent route | Attack and kill the creature, then loot the caps | The mushrooms, plus combat experience, and the cook's quest still completes |
The creature's transformation branch is the memorable one. It thanks you for keeping its kin safe, releases a cloud of golden spores, and shows a dragon-like eye opening beneath the mountain before your party's portraits twist into squat, smiling mushroom versions of themselves. The second video in the reference set, "My entire party turned into mushrooms…", documents this path in full, while the same creator later reloaded a save to test killing the creature instead. Killing it works, and the cook accepts the stolen caps without complaint, so the Underkeep mushroom for improvement quest has a pragmatic third outcome rather than only a moral fork.
Practical Tips Before You Head Back
- Loot the mushroom creature's chamber. The pickaxe is the gate to the fifth cap, and skipping it means a long walk back.
- Save before the handover. Both hand-in outcomes trigger immediately, and the demo does not warn you.
- Rest is cheap but not free. Camping consumes shared food, so bank a few edible drops from worms and rats before a long dungeon push.
- Right-click your active skill slot to swap between unlocked skills, per the tutorial. Some skills require a specific weapon type, so a weapon upgrade can quietly disable an ability you were relying on.
- Clear the forest properly. The snake hole near the strange rock outcrop hands out 40 experience and a Beast Bane ring that adds bonus damage against animals, which is useful before the rat fight at the merchant's cart.
- Turn in place freely. Monsters only move when you take a movement or attack action, so rotating to check your back costs you nothing.
FAQ
How many mushrooms do you need for the Underkeep mushroom for improvement quest? Five. Two are outdoors in the forest, and three are inside the cave or mine, including one inside a crate and one behind the rubble pile.
Why can't I break the rock pile with my sword? Because the rubble is not a combat object. Once the pickaxe is in your inventory, left-click the pile itself. Swinging a weapon or right-clicking will not clear it.
Can you complete both rewards in one playthrough? No. Handing the caps to the fungal creature consumes them, so the cook's request cannot also be fulfilled. Attacking the creature lets you keep the mushrooms for the cook, but you lose the spore vision branch.
Is the mushroom quest the end of the demo? For reference only, accounts conflict: the cited playthrough is described here as showing a post-scene message that the demo continues, while a Steam community report calls the mushroom result one of the demo's endings and a November 2, 2026 hands-on describes the polite mushroom route as an alternate game over. Verify the current demo build before treating either account as definitive.
The Underkeep mushroom for improvement quest is a small fetch task that quietly teaches everything the game wants you to know: read your environment, question the second quest-giver, and never assume a rock pile is just decoration.
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